This paper examines the mentality of the priests themselves, their rationale for going to war, their motivations and expectations, and their interpretation of their experiences. Sources include a sample of the published letters and memoirs of some thirty priests in both combat and non-combat positions as well as compilations of letters, archival documents and secondary material. The paper raises the question of the relationship between religion and patriotism. Did religious beliefs actually support patriotism rather than pacifism? Did the priests see their participation in the war as an opportunity to reconvert their countrymen, to bond with them, and/or to sustain their courage and patriotism? Did the priests in combat positions agonize over their role? How were they regarded by military authorities and soldiers? Did they expect to be better integrated into French society after the war? Did they seem to be trying to prove their patriotism in order to be accepted again as full participants in French society?